New insights into human immunity from ancient genomics

Population genetic studies have clearly indicated that immunity and host defense are among the functions most frequently subject to natural selection, and increased our understanding of the biological relevance of the corresponding genes and their contribution to variable immune traits and diseases. Herein, we will focus on some recently studied forms of human adaptation to infectious agents, including hybridization with now-extinct hominins, such as Neanderthals and Denisovans, and admixture between modern human populations. These studies, which are partly enabled by the technological advances in the sequencing of DNA from ancient remains, provide new insight into the sources of immune response variation in contemporary humans, such as the recently reported link between Neanderthal heritage and susceptibility to severe COVID-19 disease. Furthermore, ancient DNA analyses, in both humans and pathogens, allow to measure the action of natural selection on immune genes across time and to reconstruct the impact of past epidemics on the evolution of human immunity.

Automated summary

Population genetic studies have shown that immunity and host defense are important functions subject to natural selection, with recent research focusing on human adaptation to infectious agents through hybridization with extinct hominins and admixture between modern human populations. Advances in ancient DNA sequencing have provided insights into the sources of immune response variation in contemporary humans, including the link between Neanderthal heritage and susceptibility to severe COVID-19 disease. Ancient DNA analyses in humans and pathogens allow for understanding the action of natural selection on immune genes over time and the impact of past epidemics on human immunity evolution.